webpack-hot-middleware 用于 livereload

https://github.com/glenjamin/webpack-hot-middleware

Webpack hot reloading using only webpack-dev-middleware. This allows you to add hot reloading into an existing server without webpack-dev-server.

This module is only concerned with the mechanisms to connect a browser client to a webpack server & receive updates. It will subscribe to changes from the server and execute those changes using webpack's HMR api. Actually making your application capable of using hot reloading to make seamless changes is out of scope, and usually handled by another library.